Because heroin abusers do not know the actual strength of the drug or its true contents, they are at a high risk of overdose or death.
Many people die from pain medicine overdoses. In fact, more people overdose from pain medicines every year than from heroin and cocaine combined.
"Effects of Pain Medicine Abuse on Brains and Bodies." National Institute on Drug Abuse (NIDA).
"2017 Drugs of Abuse." Drug Enforcement Agency (DEA).